Design of new anode materials based on hierarchical, three dimensional ordered macro-mesoporous TiO2 for high performance lithium ion batteries

Abstract

As anode materials for lithium ion batteries, two three dimensionally ordered macroporous TiO 2 , one with disordered inter-particle mesopores formed by the aggregation of nanoparticles (3DOM) and another with inner-particle mesopores generated by a surfactant templating strategy (3DOMM), have been synthesized using poly(styrene-methyl methacrylate-3-sulfopropyl methacrylate potassium) (P(St-MMA-SPMAP)) spheres as a hard template and their electrochemical properties are compared. SEM and TEM observations reveal that both 3DOM TiO 2 and 3DOMM TiO 2 have well-ordered macropores and interconnected macropore walls with a regular periodicity. 3DOMM TiO 2 demonstrates a specific surface area of 139 m 2 g À1 , which is higher than that of 3DOM TiO 2 (99 m 2 g À1 ) due to the smaller crystallite size and inner-particle mesopores. The electrolyte adsorption results show that both 3DOM TiO 2 and 3DOMM TiO 2 have similar adsorption capacities despite a difference in the surface area. Electrochemical impendence spectroscopy analysis shows that 3DOMM TiO 2 has a lower charge transfer resistance and faster Li + diffusion coefficient than 3DOM TiO 2 . Moreover, both 3DOM TiO 2 and 3DOMM TiO 2 possess excellent initial capacity of 248 mA h g À1 and 235 mA h g À1 at 0.2 C and 208 mA h g À1 and 202 mA h g À1 at 1 C, respectively. The reversibility study demonstrates that the 3DOMM TiO 2 displays higher cycling capacity, superior rate behavior and higher Coulombic efficiency because the higher surface area provides more active sites and the presence of the inner-particle mesopores in the walls of macropores serve as a bicontinuous transport path and affords a shorter path length for diffusion of Li ions compared with the 3DOM TiO 2 and its crystallite aggregated mesopores. The reversible capacity of 106 mA h g À1 observed for the 3DOMM TiO 2 can be retained after 200 charge-discharge cycles at a relatively high current rate of 4 C. This cycle stability performance can be equally attributed to the crystallite size and inner-particle mesopores in the 3DOMM TiO 2 . Moreover, the existence of a bicontinuous porous structure in the 3DOMM TiO 2 can further enhance the lithium insertion/extraction capacity at high rates. We believe that this study can shed light on the 3DOMM structure as a promising material for highly enhanced performance in lithium ion batteries.

Improvement of photocatalytic activity of silicate paints by removal of K2SO4

“…It is known that only a thin layer of a photocatalytic material takes part in the photooxidation reactions, because absorption of UVeVis light is limited by the depth and porosity of material, macro and mesopores network. Several studies showed that the hierarchically macro-mesoporous TiO 2 structures exhibited an important light harvesting effect of the macrochannels allowing light waves to penetrate deeper inside the photocatalyst (Jin et al, 2014). Therefore the porosity of the photocatalytic paint layer and the macromesoporous structure will be important in their photocatalytic activity.…”

Nanoporous TiO2/Co3O4 Composite as an Anode Material for Lithium-Ion Batteries

“…It is noted that among various nanosized structures the nanoporous architecture has been considered an optimal structure for lithium insertion and extraction [29][30][31] [32,33]. Recently, dealloying was further extended to fabricate the metal oxide nanomaterials [34].…”

Atomic layer deposition derived amorphous TiO2 thin film decorating graphene nanosheets with superior rate capability

“…Third, as shown in Fig. 2e, the wrinkled and curved gossamer-like GNSs with high electrical conductivity overcomes the TiO 2 disadvantage of low electrical conductivity, which facilitates lithium insertion/extraction kinetics [28,29]. Forth, the uniform amorphous TiO 2 film reduces path length for Li-ion diffusion and benefits from activation process.…”